Throat plate for sewing machines



Aug. 12, 1930. w. F. LAUTENSCHLAGER 1,773,046

THROAT PLATE FOR SEWING MACHINES Filed Oct. 16. 1928 /6 In v fl/Ol m -54: (mm y wwgmmg Patented Aug. 12, 1930 UNITED STATES PATENT OFFICE WILLIAM F. LAUTENSCHLAGER, OF CINCINNATI, OHIO, ASSIGNOR TO PEERLESS MA- CHINERY COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS THROAT PLATE FOR SEWING MACHINES Application filed October 16, 1928. Serial No. 312,838.

This invention relates to throat plates for sewing and like machines and is more particularly adapted for those machines in which the throat plate is provided with a needle slot permitting a series of stitches back and forth as in a zigzag machine.

In a machine of this character using a throat plate having a pair of needle holes joined together by a slot, there is a tendency for the stitching to pull the material, especially light material, down into the slot when the thread is tightened which results in puckering and distorting the work. v

The main object of the invention is the provision on a throat plate having a needle slot of means for supporting the work over the said slot to prevent it being drawn into the slot and puckered and distorted by the stitches.

Another object of the invention is the pro vision of a device capable of rapid application to and removal from the throat plate.

An additional object of the invention is the provision of means of the character specified which will not interfere with the removal of the work from the throat plate or the feeding of the work during a continuous stitching op eration.

Other objects of the invention will be more specifically described and set forth herein after. 4 y

In its preferred embodiment, my invention contemplates a thin resilient tongue adapted to be mounted on the throat plate with its end overlapping the central portion of the needle slot leaving sufiicient space on both sides of the tongue for the passage of the needle or needles, said tongue facing in the direction of the normal feed of the machine in order to permit the work to be fed normally without interference from the tongue.

Preferably. the tongue decreases in width toward its end so that stitches laid in the material and around the end of the tongue may be tightened thereon without preventing the normal feeding of the work from drawing the stitches ofl the end of the tongue as the work is fed forward and also, in case when a plurality of stitches are laid while the work is stationary to permit the work to be withdrawn from the machine and the loops to slip off the end of the tongue. Y V

In the accompanying drawings illustrating one form of the invention, Figure 1 is a top plan view of a throat plate having a needle slot and a work supporting member constructed and adapted to be operated in accordance with my invention; Fig. 2 is a side elevation of the same; Fig. 3 is a transverse sectional view looking from right to left on line 33 in Fig. 1 and Fig. 4 is a sectional View on an enlarged scale looking in the same direction and partly in elevation on line 44 in Fig. 1.

For the purposes of illustration, there is shown a throat plate 10 of substantially rectangular form having one corner 12 cut away. The throat plate is provided with suitable screw holes 14 whereby it may be fastened to a supporting part of the machine for which it is designed. In its forward end is located .a needle slot 16 formed by piercing the plate with two needle holes and then connecting them with a slot. The front portion of the plate is preferably made of less thickness than the remaining portion and the walls of the needle slot 16 areundercut so that the thread used in forming the stitching will slide over.

smooth rather than angular surfaces.

It is to be understood that the form of throat plate shown herein is for purpose of illustration only since the throat plate may be constructed in various forms and of different thicknesses in order to accommodate itself to the particular machine upon which it is used and that the needle slot may be variously located in the throat plate and may be of various shapes.

In the form of the invention shown, a tongue 20 is adjustably and removably mount-- ed on the throat plate with its end overlapping the central portion of the needle slot 16. For holding the tongue in position on the throat plate any suitable means may be provided, one such means being shown compris ing a plate 22 held on the throat plate by screws 24 which when set up will cause the plate to bindthe shank end of the tongue inserted thereunder. The tongue may be of'any suitable form but as shown is elongated, di-

a ti e minishing in width toward its end, the latter being rounded and of a width to cover the central ortion of the needle slot leaving the needle oles suificiently exposed to permit passage of the needles therethrough and the threadto be laid thrqpgh the work and around the to e- In order that the tongue may not interfore or restrict the feeding forward of'the week, it should face in the direction of the normal feed of. the machine so that as the work is fed forward as, for instance, in the case of zig zag stitching, the stitches will pull oil the end of the tongue which releases slightly to permit this action. It is 1mportent in this connection that the end of the ton e should. overlap the needle slot ust an ciently to suppo The end of the to e should be of verythin resilient mate- 29 that it will yield readily to permit withdrawal of the stitches and so that its will not tend to unduly decrease the siae of the loops of. thread land through the material in the stitching process and thereby 2,; lt'in. a looseness of the stitches when the we; is drawn ofi the tongue. This looseness of stitches ma be prevented by having the diameter of the tongue at the needle'slot slightly less than'the distance between the 30, slots in which so the material will be drawn, down by the st tches around the sides of't he tongue and sl ghtly puckered which disappearsafter stitches have been drawn oflt e end of the tongue. This is illustrated ure 4 onan enlarged scale. e operation of my device is extremely simple and is as follows. The tongue is adme e a o n n Fi tip jilst overlappingt e needle slot midway i0, not interferlng with the needle holes and the passage of the needleor needles therethrough. The work 3Q is placed on the throat plate Qyer the tongue and the machine is then operated in the usual manner, The loops of $5 the stitchi through the material will onthe en of the tongue and when drawn tr w ll l draw down the material on the desnf the tongue thereby puckering it to V a. FI E t W $15 the end of the tongue ,9. is wedge. shaped the work may be fed forfi i'tl d h S i h s drawn off the end of the to igpe without obstruction which relieves the tension on the loops of the thread and ripits the work to smooth out. It will be "it 't,a ton ue oft is construction does :n ter lbre wfih the eeding of the Work ilie am lli: The $3 11 u tis se- 1 @W ta s u ed inimising a P W9 l w terse su s Q mo e aye ia etprml l ll: Q! sewing 011 but ons is an if iii k b i P. .9 trewn. an. e drawn on h .9 t t e wreat s tissue being raised was the a lidrawel oi the re 1 with its extreme fi d up n h comp et n f- It is to be understood that my invention is not to be limited to the exact form herein shown and described but may be embodied in other forms of construction all within the purview of the following claims.

What I claim is:

1. A throat plate having a pair of needle holes spaced apart and connected together by a slot in combination with an elongated, flat, flexible tongue having converging sides and removably mounted at one end on said plate with its other end extending entirely across said slot in engagement with the top surface of said plate adjacent both sides of said slot for supporting the work thereabove and for preventing the work bein drawn down into said slot by stitches; said tongue being sufliciently resilient to permit its end being raised from said top surface for withdrawing the stitches therefrom.

2. A throat plate provided with a needle slot in combination with an elongated, flat, thin resilient tongue having converging sides and adjustably and removably mounted at one end on the top face of said throat plate with its other end extending entirely across the. central portion of said slot in position to be supported by the portions of the throat plate adjacent said slot, said tongue facing in the direction of the normal feed of the work to permit stitches laid in the work around the end of the tongue to be Withdrawn therefrom by raising, the end of said tongue from said plate as the work is fed forward.

3. A throat plate having a pair of needle holes spaced apart and connected. together by a'slot in combination with an elongated, thin flexible tongue removably mounted at one end on the top surface of said throat plate and having its other end relatively narrow and extending entirely across the central portion of said slot for supporting the work thereabove and for preventing it being drawn downwardly into the slot by stitches made around the end of said tongue; said tongue being sufiiciently resilient to permit the stitches around said tongue to be withdrawn therefrom by raising the end of said tongue from the top surface of said plate.

In witness whereof, I hereunto set my hand this 13th day of October, 1928.

WILLIAM F. LAUTENSCHLAGER. 

